Spectrometry
question:spectrometry

The Public Lab spectrometry project is an open source community effort to develop low-cost spectrometers for a range of purposes. All open spectrometry hardware and software efforts are welcome here! **Join in by:** * Learning [what spectrometry is](#Whats+spectrometry) * Reading about goals and [asking great questions](#Frequently+Asked+Questions) * Building a basic spectrometer using [one of our starter kits](#Starter+Kits) * Trying (and critiquing) our [community-made how-to guides](#Activities) and posting your own * Building on others’ work; hack and remix the kits to refine and expand them * [Share your upgrades](#Upgrades) for others to try -- and perhaps for inclusion in an upcoming starter kit release or add-on kit **** ## Starter Kits Public Lab’s Kits initiative offers several starter kits, including many of the basic components, and instructions for constructing a basic visible light spectrometer. The point of the kits is to provide a shared reference design for building experimental setups onto. Lego Spectrometer Kit Our most recent kit, incorporating community improvements while balancing low cost and ease of construction. Choose between webcam and Raspberry Pi camera versions and build attachments width standard Lego connectors. Build one Buy one Papercraft Spectrometry Intro Kit A $9 paper spectrometer which you can attach to a smartphone or webcam. It’s made of paper to reduce cost and complexity, and is mainly intended as an “introductory” or educational kit. The flat design can be printed on a laser printer or photocopied to make more. Build one Buy one **** ## Activities This is a list of community-generated guides for specific applications using your spectrometry setup (either a [starter kit](#Starter+Kits) or a [modded design](#Upgrades)). These [activities can be categorized](https://publiclab.org/wiki/activity-categories), and some may be more reproduced -- or reproducible -- than others. Try them out to build your skills, and help improve them by leaving comments. Together, we can repeat and refine the activities into experiments. > **Note:** If you are working on an **urgent issue** such as a threat to your or someone else’s health, please know that these techniques may not be ready for your use; it's possible that they never will be. [Read more here](/notes/gretchengehrke/09-29-2016/common-low-cost-technique-limitations) ### Activity grid [activities:spectrometry] **** ## Upgrades Have you added to your starter kit, improved it, or redesigned it? Show others how to take it to the next level by posting a build guide here: [upgrades:spectrometry] Add your upgrade guide here Request or propose an upgrade _Mods should include a parts list and a step-by-step construction guide with photo documentation. See an example._ **** ## Challenges We're working to refine and improve DIY spectrometry on a number of fronts; here, take a look at the leading challenges we're hoping to solve, and post your own. For now, we're using the Q&A feature, so just click "Ask a question" to post your own challenge. Be sure to add: * constraints: expense, complexity * goals: performance, use cases [questions:spectrometry-challenge] **** ## Builds There’s a lot going on in open source spectrometry -- if you’ve developed another open source design you’d like to show others how to construct, post it here! * [RamanPi](https://hackaday.io/project/1279-ramanpi-raman-spectrometer) * [Hackteria “drop”-style spectrometers](https://publiclab.org/notes/gaudi/04-03-2014/diy-micro-volume-spectrophotometer) / [DIY NanoDrop on Hackteria.org](http://hackteria.org/wiki/index.php/DIY_NanoDrop) * _Add yours here_ ##What's spectrometry? Colored light is often a blend of different colors. A spectrometer is a device which splits those colors apart, like a prism, and measures the strength of each color. A typical output of a spectrometer looks like this spectrum of the daytime sky, with the actual light spectrum at the top and the graph of wavelength (horizontal axis, in nanometers of wavelength) and intensity (vertical axis) below: [![sky.png](https://i.publiclab.org/system/images/photos/000/005/455/original/sky.png)](https://spectralworkbench.org/analyze/spectrum/19882) > Needed: overview of spectra, calibration, units, comparison, and fluorescence/absorption. Please edit this page or link to a resource, potentially [the Wikipedia page](https://en.wikipedia.org/wiki/Spectroscopy), although that's quite full of technical jargon. ## Software Spectral data can be analyzed with https://spectralworkbench.org to create spectra plots, find centers of emissions plots, and find similar spectra. Data also can be exported in various formats (JSON, CSV, XML) for further analysis and visualization. ## How does this compare to a lab instrument? The [Desktop Spectrometry Starter Kit](/wiki/desktop-spectrometry-kit-3-0) is only one part in an experimental setup, and the following shows where it fits in an overall diagram of a lab spectrometric setup: [![tmp_31873-IMG_20161027_101601_2-79757779.jpg](https://publiclab.org/system/images/photos/000/018/635/large/tmp_31873-IMG_20161027_101601_2-79757779.jpg)](https://publiclab.org/system/images/photos/000/018/635/original/tmp_31873-IMG_20161027_101601_2-79757779.jpg) [![tmp_31873-IMG_20161027_095939_2-108076392.jpg](https://publiclab.org/system/images/photos/000/018/636/large/tmp_31873-IMG_20161027_095939_2-108076392.jpg)](https://publiclab.org/system/images/photos/000/018/636/original/tmp_31873-IMG_20161027_095939_2-108076392.jpg) There are many, many different types of spectrometry and spectrometers -- many don’t even measure light. Even among those that do, some detect light in the ultraviolet range, and others in the infrared range of light. The range of Public Lab spectrometers depends on the range of the commercially available cameras we attach them to (~400-700 nanometer wavelengths). A commercially available product with a slightly wider range (from 335 to 1000 nanometers) is [available from Cole Parmer](http://www.coleparmer.com/Product/Cole_Parmer_Visible_spectrophotometer_335_to_1000_nm_wavelength_range_analog_output/UX-83055-10). **** ## Frequently Asked Questions [questions:spectrometry] Note our previous Frequently Asked Questions page, which [can be found here »](/wiki/spectrometer-faq) -- please help port these into the new system, here!...


Author Comment Last activity Moderation
viechdokter "Ah, okay, I forgot about the "%" sign. I knew I was missing something. Just didn't know what exactly. Thanx for the quick answers. " | Read more » over 8 years ago
dhaffnersr "hey viechdokter, the "scratched off" ccd screen, is the color film on the sensor's surface, very tricky and very risky to attempt it, but what hap..." | Read more » over 8 years ago
cfastie "In Spectral Workbench the Y-axis on the spectrogram is "Intensity (%)." If you took the sum of all three channels and plotted them on the same grap..." | Read more » over 8 years ago
warren "Hi, Georgi - are you asking about Spectral Workbench? We expect JPG data, mostly -- you can read more in @stoft's notes about characteristics of th..." | Read more » over 8 years ago
leanr "yes, by and electric arc, so it vaporize the metals. " | Read more » over 8 years ago
warren "Does it burn or otherwise affect the surface it's pointed at? Cool. " | Read more » over 8 years ago
leanr "it gives you the spectrum of the examined metal or alloy " | Read more » over 8 years ago
warren "Whoa, what does a metascop do? " | Read more » over 8 years ago
warren "I haven't found a technique that worked for all phones but some apps let you fix infinity focus. " | Read more » over 8 years ago
warren "If you're at all interested in reflectance measurements, I posted a sketch for a reflectance setup here that might interest you: https://publiclab...." | Read more » over 8 years ago
FortunaWolf "Forager bees work only 1 species of flower on any single flight, so when you collect individual pollen packets from returning forages they are mono..." | Read more » over 8 years ago
viechdokter "Two thoughts: first, the bees sometimes bring in different sorts of pollen, its not 100% sorted although the bees "try to" sort. second, I'd gues..." | Read more » over 8 years ago
FortunaWolf "I wonder if you could do raw data capture off of the webcam (that would also help with your autogain issues too). By removing the bayer filter you ..." | Read more » over 8 years ago
warren "The camera is listed here: https://publiclab.org/wiki/desktop-spectrometry-kit-3-0#Parts+List I think a B&W one would be great, but I really d..." | Read more » over 8 years ago
FortunaWolf "Hi Warren, I don't know what resolution I need yet, TBH. Initial data from the RGB data from cell phone cameras shows that knowing the geographic l..." | Read more » over 8 years ago
warren "Hi, FortunaWolf - what resolution do you need, is probably the first question. I think the DVD will probably not be the limiting factor but if the ..." | Read more » over 8 years ago
leanr "Thanks Chris, the images are from the metascop manual. The camera on the images is an analogic one from the '70ies, I would love to know if and ho..." | Read more » over 8 years ago
cfastie "That looks like a real find. I suspect some experimentation will be required to get photos of the spectra. The spectral image is probably not..." | Read more » over 8 years ago
warren "Hi! We just released a Node.js version of the core library here: https://github.com/publiclab/spectral-workbench.js I think it'd be possible to ta..." | Read more » over 8 years ago
cfastie "cjtiaan, Were you able to download the raw data from SpectralWorkbench? There are links for that on each spectrum page. Chris " | Read more » over 8 years ago
warren "Hi, cjtiaan - if you're looking for the absolute brightness, you may need to do a gain correction, which you can read about here: https://publiclab..." | Read more » over 8 years ago
cfastie "So you already have the result you want, but you have to write another program to do the same thing? I can't help with that, I'm not a programmer. " | Read more » over 8 years ago
cjtiaan "@cfastie thank you for your respons. I want to determine the Luminous flux of the light. Which means I want to measure the intensity in lumens of..." | Read more » over 8 years ago
cfastie "Define power. what are some possible units of power in this case? Chris " | Read more » over 8 years ago